Superficial, Cutaneous and Subcutaneous Mycoses

Question 1

what are the three cutaneous mycoses?

Answer 1

dermatophytosis, tinea versicolor and tinea nigra

Question 2

how prevalent is dermatophytosis? what fungus causes it?

Answer 2

it is very common caused by three different genera of fungi- epidermophyton, trichophyton and microsporum

Question 3

what does dermatophytosis infect? what are the symptums called?

Answer 3

infect superficial keratinized structures.

symptoms are called tinea

Question 4

what three known syndromes are caused by dermatophytosis?

Answer 4

jock itch, athlete’s foot and ringworm

Question 5

how is dermatophytosis transmitted?

Answer 5

by fomites or autoinnoculation

Question 6

how is dermatophytosis diagnosed?

Answer 6

by KOH mount, culture, PPD or woods lamp exam

Question 7

how is dermatophytosis treated?

Answer 7

treat all affected body sites simultaneously wiht topical antifungal cream or treat with oral griseofulvin

Question 8

how does tinea versicolor appear? what is it caused by?

Answer 8

hypo or hyperpigmented areas on the trunk, back or abdomen. caused by overgrowth of normal flora Malassezia

Question 9

how is tinea versicolor diagnosed? treated?

Answer 9

KOH mount of skin scrapings

treat with selenium sulfide cream or oral azoles

Question 10

how common is tinea nigra? what is it caused by?

Answer 10

uncommon

infection of injured extremity by soil organism werneckii

Question 11

what does tinea nigra look like? what can it be confused with?

Answer 11

is a dark brown spot that may be confused with melanoma

Question 12

how is tinea nigra diagnosed?

Answer 12

by KOH mount for thick septate branching hyphae with dark pigment in walls. can also culture on sabouraud’s agar at room temperature for shiny black colonies

Question 13

how is tinea nigra treated?

Answer 13

with tipical salicylic acid and topical azole

Question 14

what are the three subcutaneous mycoses?

Answer 14

sporotrichosis, chromomycosis and mycetoma

Question 15

what is sporotrichosis caused by? what is its morphology?

Answer 15

sporothrix spp. thermally dimorphic fungi

Question 16

how is sporotrichosis transmitted?

Answer 16

enters the skin through small injuries (thorns and splinters) from vegetation

Question 17

what are the symptoms of sporotrichosis?

Answer 17

painless ulcer at the site of puncture spreads up the lymphatic over the years

Question 18

when is sporotrichosis pulmonary?

Answer 18

when there is COPD

Question 19

what may happen with sporotrichosis infection in immunosuppressed patients?

Answer 19

disseminated or meningial infection

Question 20

how is sporotrichosis diagnosed?

Answer 20

by biopsy with round or cigar shaped yeast

if cultured at room temp from pus there will be hyphae and conidia

Question 21

how is sporotrichosis treated?

Answer 21

oral azoles. more serious forms may need to be treated with Amphotericin B

Question 22

what is another name for chromomycosis? what is it caused by?

Answer 22

chromoblastomycosis

caused by injuries to the feet that are infected by a variety of tropical soil fungi

Question 23

what does chromomycosis look like?

Answer 23

looks like gradually spreading wartlike or plaque lesions with scattered black dots

Question 24

how is chromomycosis diagnosed?

Answer 24

KOH mount shows gray or black septate hyphae or conidia. if the dark spots are biopsied, there would be round fungal cells inside leukocytes or giant cells

Question 25

how is chromomycosis treated?

Answer 25

with a combination of flucytosine, itraconazole, local surgery and heat

Question 26

how prevalent is mycetoma? where does it infect and what organism is it caused by?

Answer 26

rare infection of wounds on extremeties

petriellidium or madurella from the soil cause it

Question 27

what does mycetoma look like?

Answer 27

forms abscesses, granulomas and pus with granules

Question 28

how is mycetoma diagnosed? treated?

Answer 28

with biopsy

treat with combination of surgery, IV amphotericin B and oral azole

Question 29

what does candida look like? what is the most common?

Answer 29

multimorphic- yeastlike, pseudohyphal and hyphal forms

most common is c albicans- normal flora

Question 30

what are the most common presentations of candidiasis?

Answer 30

thrush (inhalers/AIDS), vaginitis and diaper rash.

Question 31

what are less common presentations of candidiasis? what are they associated with?

Answer 31

hand infections (dishwashers), folliculitis, chronic mucocutaneous (with genetic cell mediated immunity deficiency) and full GI infections associated with leukemia

Question 32

when are candidemia and disseminated disease a concern?

Answer 32

with patients with cell mediated immune deficiency

Question 33

how is candidiasis diagnosed?

Answer 33

by exam, biopsy, culture and/or CT

Question 34

how is candidiasis treated?

Answer 34

treatment ramps up with severity of disease. topical azoles for superficial, graduating to oral azoles and then adding amphotericin b for life threatening infections

Question 35

what is a major concern with candidal infections, especially in the hospital setting?

Answer 35

drug resistance. should evaluate in culture before administering antifungals